Nico Rosberg is sounding far from defeated ahead of the Spanish grand prix.
The German, although still leading the drivers' world championship by a few points, has seen his teammate Lewis Hamilton w...

Nico Rosberg is sounding far from defeated ahead of the Spanish grand prix.

The German, although still leading the drivers' world championship by a few points, has seen his teammate Lewis Hamilton win the last three races on the trot.

But far from expecting to fall in line behind the Briton when the battle resumes in Barcelona, Rosberg on Monday told German television RTL his plan for Spain is "full attack".

"To know I have the fastest car to drive is so inspiring," said the 28-year-old.

Rosberg said the goal for Barcelona is not to hold Hamilton off but to "extend the championship lead", which will almost certainly require him to beat his on-form teammate on the track.

He won in Australia when Hamilton retired, but in Malaysia, Bahrain and China, Rosberg saw the other Silver Arrows with the upper hand.

Bahrain, however, was a true and rare wheel-to-wheel battle, with Rosberg claiming that when all was well with the two Brackley-built cars in 2014, the Mercedes pecking order is "undecided".

"I was better in the dry, him in the rain," said Rosberg.

Hamilton has also hogged the qualifying limelight so far this year, but last year at the Circuit de Catalunya, it was Rosberg on pole ahead of the 2008 world champion.

Now, "pole position will be very important for the battle with Lewis" this weekend, said a feisty Rosberg ahead of the 2014 Spanish race.

Hamilton and Rosberg's relationship dates right back to their boyhoods, but suddenly the prize is the biggest one in the entire world of motor sport -- the F1 title.

Rosberg admits that is making their personal relationship "a bit harder" than in the past.

"But luckily we have experienced it all before, even right back to karting," he said.